Problems have been encountered in changing appliances, etc. (especially gaseous fuel appliances and gas fireplaces/fireplace log sets) from natural gas to LP or other fuel. This is due to the fact that the existing designs for pilot assemblies are normally supplied from the factory with an installed pilot assembly designed for the intended fuel use and are not conducive to rapid changeover to another fuel nor to field replacement. A need for an easily convertible/replaceable pilot assembly has long existed.
The following US Patent references are noted:
U.S. Pat. No. 3,913,846: discloses a gas orifice 30 and gas supply pipe 28 sealingly secured by mounting socket 22, compression nut 24, and compression fitting 26. See FIG. 1. PA1 U.S. Pat. No. 5,339,630: discloses a fuel nozzle and a sealing member, such as copper washer 106, placed between air housing 82 and shoulder 108 of the nozzle to create a sealing interface. See FIG. 2. PA1 U.S. Pat. No. 3,367,684: discloses a pressure tube-to-pipe fitting including a fitting body 10, a nut 12, and a two-part integral locking ring and gasket assembly 14. When tube section 16 is attached to body 10, fitting 18, and gas distribution pipe 20, there is attached a sealed, leak-proof connection which will not pull apart. See FIG. 3. Further, see column 2, lines 70-72, column 3, lines 58-75 and column 4, lines 1-10. PA1 U.S. Pat. No. 4,678,428: discloses a fuel burner with a gas supply base 16 having a nozzle 3 mounted by a rubber packing 17 on base 16 under compression forces exerted by ring-shaped coupling member 4. PA1 U.S. Pat. No. 3,365,219: discloses a pressure fitting for a tube joint. Fitting 10, nut 12, frusto-conical locking ring 14, sealing ring 16, and thrust washer 18 are employed for the attachment of tube 20 to gas pipe 24. See FIGS. 1, 2, and 5. See column 3, lines 43-52. PA1 U.S. Pat. No. 3,072,421: discloses a coupling assembly including washer 7 in nipple 17 with the base of the washer abutting flange 12. See FIGS. 1-4. PA1 U.S. Pat. No. 2757945: discloses a sealed pipe joint member 10 including apertured member 12, pipe 16, and spring steel, truncated-cone locking washer 14. See FIGS. 1 and 2. PA1 U.S. Pat. No. 2,456,203: discloses a coupling for a tubular member. Nut 16 is threadedly coupled to body 14. The body has a shoulder for receiving resilient washer 18 for sealing between tube 12 and the body. See FIG. 3. PA1 U.S. Pat. No. 2,450,170: discloses a nut 10, pipe 13, and sealing washer 31 for sealing between pipe 13 and shoulder 28. See FIG. 1. PA1 U.S. Pat. No. 5,551,867: discloses a furnace conversion unit with a compression member 18. See FIG. 4. PA1 U.S. Pat. No. 3,164,890: discloses a packing retainer 8 assembled on coupling member 2 with boss 1. See FIGS. 1, 2, and 5-7.
The following US Patent references may also be of interest: U.S. Pat. Nos. 4,346,923, 4,346,919, 1,725,975, 1,516,397, 3,058,760, and 2,236,031.